We intend to analyze non-histone proteins (NHCP) from parental and variant mouse plasmacytoma cell lines by high resolution two-dimensional gel electrophoresis. Certain NHCP are believed to play a role in the specific regulation of gene expression and possibly in neoplastic transformation. Our variant plasmacytoma lines differ from the parental lines in their ability to synthesize heavy and light immunoglobulin polypeptide chains; we will examine these lines for qualitative or quantitative changes in NHCP which may be correlated with heavy or light chain synthesis. A second objective of the work is to develop methods for the immunospecific isolation of individual NHCP. Specific antisera will be prepared by immunization with small amounts of individual NHCP isolated from two-dimensional gels. Solid immunoabsorbents prepared from the specific antisera will then be used to isolate larger quantities of the same NHCP from crude preparations of total NHCP. If the method is successful, it may become possible to isolate sufficient quantities of individual NHCP for expanded physical and biochemical studies on their structure and function.